S H 



A PRACTICAL METHOD OF SPONGE CULTURE 



From BULLETIN OF THE BUREAU OF FISHERIES, Volume XXVIII, 190S 

Washington, igo8 



Proceedings of the Fourth International Fishery Congress 




WASHINGTON :::::: GOVERNMENT PRINTING OFFICB: 



191U 




Class 
Book 






A PRACTICAL METHOD OF SPONGE CULTURE 



From BULIvETIN OF THE BUREAU OF FISHERIES, Volume XXVIII, 1908 

Proceedings of the Fourth International Fishery Congress : : Washington, 1908 




riU'Ax 



WASHINGTON :::::: GOVERNMENT PRINTING OFFICE 



1910 






BUREAU OF FISHERIES DOCUMENT NO. 669 
Issued March. 1910 



' ■= -fe 19i0 






A PRACTICAL METHOD OF SPONGE CULTURE 



By H. F. Moore 

Scientific Assistant, United States Bureau o/ Fisheries 



Paper presented before the Fourth International Fishery Congress 
held at Washington, U. S. A., September 22 to 26, 1908, and 
awarded the prize of $100 in gold offered by Hayes Bigelow for the 
best demonstration, based on original investigations and experiments, of 
the commercial possibilities of growing sponges from eggs or cuttings 



CONTENTS. 

Page. 

Conditions and needs of the sponge fisheries 547 

Previous experiments in sponge culture 550 

Possible lines of experiment: 

Grafting 553 

Growing from eggs 554 

Growing from degenerative bodies and dissociated tissues 555 

Growing from cuttings 555 

Propagation of sponges from cuttings: 

Seed sponges 555 

Cuttings ■ 557 

Attachments 559 

Planting 56<J 

Rate of growth 5*59 

Mortality 57^ 

Shape and quality 57^ 

Harvesting 579 

Transportation and acclimatization 580 

Economic application of the method: 

Essential considerations 581 

Financial aspects 5^3 

546 



BuL. U. vS. B. F., 1908. 



Platk LXVII. 





SPONttF.S (IROWINd OX CF.MKNT TRIANULKS TTSED IN KXPKRI MKNTAI, PLANTS OF CI'TTI 



A PRACTICAL METHOD OF SPONGE CULTURE. 



By H. F. MOORE. 
Scientific Assistant, United States Bureau of Fisheries. 



CONDITIONS AND NEEDS OF THE SPONGE FISHERIES. ' 

As has been shown elsewhere, « ah or most of the important sponge beds 
of the world are being fished in such manner as to give more or less grave 
concern as to their' depletion. In the Mediterranean, the Bahamas, Cuba, and 
Florida the danger of commercial extinction is exciting discussion among the 
thoughtful, though often denied by the more shortsighted of those who are 
most intimately concerned, the persons who as fishermen and dealers are 
dependent upon the sponge fishery for a livelihood. The reasons for the immi- 
nence of this danger the writer has elsewhere discussed and the condition is 
here taken for granted. 

Statesmen, men of science, and men of affairs have all taken part in the 
discussion of the measures necessary to perpetuate the supply of this com- 
mercially valuable and almost essential product, viewing the situation not only 
from the standpoint of the sponge fisherman and the dealer, but from the more 
important view of the consumer, who can find no satisfactory substitute for the 
sponge in many of its applications to the arts and domestic uses. It is indubi- 
table that the threatened extinction of many of the beds is due to the employ- 
ment of methods of fishing which are in themselves destructive, and that, 
especially in Florida, the Bahamas, and Cuba, a still greater danger lies in the 
improper use of methods which, properly controlled, would be open to no reason- 
able objection. 

The illegitimate taking of small sponges on the Florida coast by both 
divers and hookers is, for instance, an almost wanton destruction of natural 
wealth. Many of these small sponges, of little practical use and worth but a 
few cents apiece, if given two years' additional growth would increase in value 
a score, and in addition would furnish myriads of larval sponges to replenish 
the bottoms bared by more legitimate operations. Every young sponge has 

« Moore, H. F. : Commercial sponges and the sponge fisheries, Bulletin Bureau of Fisheries, vol. 
XXVIII, 1908, p. 399-511. 

547 



548 BULLETIN OF THE BUREAU OF FISHERIES. 

commercial potentiality both as an individual and as a parent, and in both 
respects its utility is vastly curtailed by premature destruction. 

Legal measures for the prohibition of especially destructive methods, and 
the regulation of abuses connected with the more legitimate means of taking 
sponges, would undoubtedly, if properly enforced, do much to make more 
remote the depletion of the beds. But aside from the difficulties encountered 
in enforcing such legislation, as is witnessed in the failure of the considerable 
navies maintained by some of the states to enforce the oyster laws, such regu- 
lation could but retard the approach and not prevent the arrival of the day 
when the product of the natural beds will be inadequate to the demands of 
the markets. Even a legitimate fishery prosecuted under the spur of an increas- 
ing demand is eventually able to exterminate for all practical commercial pur- 
poses any sedentary organism toward which it may be directed. 

When the demand is light and prices consequently low, as they were for 
many years after the discovery of the Florida beds, the more populous grounds 
only may be worked with profit. When the sponges become so few and scattered 
that the time spent in looking for them greatly exceeds that expended in actually 
taking them from the bottom, profits are reduced to a degree when a closed 
season is automatically established by the removal of the spongers to other and 
denser grounds, and an opportunity is given for the replenishment of the beds 
by natural means. As the demand increases and the product becomes more 
valuable, more persons are attracted to the fishery, the methods become more 
efficient, and the degree of depletion of the beds, serving as a deterrent to further 
operations, more nearly approaches the limit of actual extinction. The beds 
are scoured year after year for the few remaining sponges, the decreasing supply 
and the increasing demand operating together to make profitable a closeness of 
search before unthought of and giving a value to small and otherwise undesirable 
sponges which in the earlier days of the fishery would have been allowed to lie 
unmolested on the bottom for want of a market. The consequence of this is that 
when a ground is finally even partially abandoned as a profitable fishery so few 
sponges are left, and these are so small in average size, that the reproductive 
capacity of the area is most seriously reduced and a long time must elapse before 
the bottom can be reseeded by nature's unaided operations. 

Some assistance could be rendered by the establishment of closed seasons, 
not so much those which prohibit fishing for a more or less restricted period each 
year, but such as would deny the right to fish on given depleted areas for terms 
of sufficient duration to permit the remaining young sponges to grow to reason- 
able marketable size and become of greater potential value in reseeding the area 
with a fresh crop of young. If such regulation could be rigorously and intelli- 
gently enforced, and if it were supplemented by measures preventing the taking 



A PRACTICAL METHOD OF SPONGE CULTURE. 549 

of Sponges of a less diameter than at least 4 14 or preferably 5 inches, the danger of 
extinction of our American beds would be eliminated; but there are certain 
serious objections which may be urged against this solution of the difficulty, 
which at best can be but a partial solution. Aside from the difficulties and 
expense of enforcing such regulations and the hardship which they may at times 
work upon the spongers, the most serious objection is that they would from 
their very nature restrict the output of the fishery, or, at best, w-ould not permit 
its development commensurately with the increasing demands of the markets. 
The writer has discussed the question at length in the paper above referred to, 
but for present purposes it appears to be advisable briefly to consider again the 
force of the last and major objection just mentioned, particularly with reference 
to the waters of the United States, although the application is general. 

That the demand for sponges is growing rapidly can not admit of dispute. 
Prior to the discovery of the beds of Florida the imports of sponges into the 
United States were insignificant, and of course none was produced at home. 
There was practically no demand, except for domestic purposes. Thirty years 
later, in 1879, the imports had increased to an average value of $100,000 to 
$120,000, while the average annual importation for the three years from 1905 
to 1907 was valued at no less than $531,745. The domestic production grew 
from nothing in 1849 to $200,000 in 1880 and an average of $658,403 per year 
from 1906 to 1908, most of which was consumed at home. In certain other 
countries also, notably Russia, Turkey, Spain, and the various states of South 
America, where very few or no sponges were formerly used, the past two 
decades have developed an important consumption. With the development of 
civilization and modern methods of industry the countries of Asia, too, are sure 
to make important demands for this practically indispensable product of the 
seas. 

No doubt new beds will be discovered. from time to time and new regions 
will come into productiveness, but it is not believed possible, in view of what is 
known of the resources of the sea in most localities in which sponges mav be 
expected to occur, that any vast areas producing the more desirable grades will 
be brought to light. If regulations governing the fisheries will merely preserve 
what we now have and will not materially augment production, there is forced 
upon us consideration of the necessity and possibility of increasing the supply 
by artificial means analogous to those employed in oyster culture or some other 
type of aquiculture. From a study of the breeding and life history of the com- 
mercial sponges two broad avenues of experiment open themselves. Research 
has shown that sponges may be propagated either in the natural sexual way by 
means of eggs, or artificially by cuttings or their equivalent. The following is a 
brief history of various observations, experiments, and suggestions in these 
directions : 



550 BULLETlxV OF THE BUREAU OF FISHERIES. 

PREVIOUS EXPERIMENTS IN SPONGE CULTURE. 

The basis of sponge culture by means of cuttings is in an observation made 
by F. Cavolini" in 1785, that sponges cut into pieces would attach to foreign 
bodies and grow. 

In 1862 Oscar Schmidt^ repeated and confirmed this observation and was 
apparently the first to make the practical suggestion that the regenerative phe- 
nomena might be utilized in the development of a system of sponge culture. 
This suggestion bore fruit in the following year when the Austrian Government 
and certain merchants of Trieste established a station on the island of Lesina, 
which in 1867 was placed in charge of Gregor Buccich. Of the experiences of 
the first four years of this work there appears to be no record, but Buccich 
submitted a report which was made the basis of a paper by Dr. Emil von Maren- 
zeller'' in 1878. 

Buccich appears to have discovered most of the salient facts relating to 
the growth of sponges from cuttings. He found that sponges can be removed 
from the water and cut in the air without injury; that in cool, damp weather 
they can be exposed to the air for eight hours without suffering material injury; 
that they can be cut and handled with less habiUty to injury during the winter; 
and that the cut surfaces will grow together or to certain foreign bodies with 
which they may be placed in contact. He observed also that apparently 
similar cuttings were sometimes dissimilar in their rates of growth, and that 
some cuttings would heal and live for years without material increase in size. 
Concerning the rate of growth, the information is indefinite. The cuttings 
were small (about i(?) inch cube) and they are stated to have doubled or 
trebled in size (bulk?) during the first year, and to have grown to a "consider- 
able size" in five years, but that seven years would be required to produce a 
commercial product. There is no statement of the actual mortality among the 
cuttings experimented with, but it is estimated, upon what basis does not 
appear, that it would not be over 10 per cent during the seven years. 

The methods employed by Buccich were various. He pegged the cuttings 
to stones, to the inside of wooden boxes, and to various other contrivances. 
In perforating the cuttings to admit the pegs, which latterly were of bamboo, 
he used "a trepan 6 miUimeters wide, fastened to a vertical turning table, 
which was kept in rapid motion by a fly wheel." The experiments were ulti- 
mately abandoned after nine years, mainly on account of the hostile attitude of 
the inhabitants. The somewhat elaborate methods of handling and planting 

a Cavolini, F. : Memorie per servire alia storia de' polipi marini. Naples, 1785. 
b Schmidt, O.: Die Spongien des Adriatischen Meeres. Leipzig, 1862. 

cVon Marenzeller, E.: Die Aufzucht des Badeschwammes aus Theilstucken. Vienna, 1878. 
Translated in Report U. S. Fish Commission, 1879, p. 771-777. 



A PRACTICAL METHOD OF SPONGE CULTURE. 55I 

the Sponge and the character of the materials employed appear to have been 
unfit for commercial application. Marenzeller observes: "As far as our present 
knowledge goes, it is certain that sponge culture will not be profitable for poor 
men, but can be only carried on successfully on a very large scale either by 
wealthy individuals or by joint stock companies." 

The failure of Buccich's work to yield commercial results appears to have 
ended experiments in Europe, but about 1879 Mr. Fogarty, a sponge buyer of 
Key West, Fla., planted 216 cuttings in a depth of about 2>^ feet of water. 
The pieces were about 2>^ inches long; they were attached to the bottom by 
sticks and wires, and it is stated that it required four months to repair the 
injuries and reestabfish growth. Four specimens, said to be six months old, 
sent to the National Museum are stated to have grown from four to six times 
the bulk of the original cuttings. This experiment was never pushed to a con- 
clusion, and the fate of the cuttings, other than those mentioned, is unknown. 
A few years later Mr. R. M. Munroe, of Cocoanut Grove, Fla., began work in 
Biscayne Bay, where for several years he experimented in fastening cuttings 
to stones and various arrangements of stakes forming hurdles and frames. A 
large proportion of the pieces survived and grew to some extent, but none 
reached a greater bulk than 3 or 4 cubic inches, and practically all were even- 
tually destroyed or lost. The bottom selected and the materials employed 
were in some cases unsuitable and in others the antagonism of some of the 
spongers prompted them to destroy the plants. At this time the first sponge- 
culture law was presented to the legislature of Florida, but it was subsequently 
so amended as to be highly objectionable and unjust to the spongers and it 
consequently failed of passage. 

About 1897-98 several thousand cuttings were planted at Sugar Loaf Key 
by Dr.. J. V. Harris, of Key West. They were attached to galvanized iron wire 
laid on the bottom, but the wire soon corroded and broke into short pieces, the 
sponges became detached, and the mortality was very high. From time to time 
I have picked up a considerable quantity of this wire with a few attached sponges. 
Growth appears to have been slow or, after a while, almost entirely arrested, and 
the largest specimens seen by me have been under 4 inches in diameter at an age 
of from 3 to 5 years, the exact age of any given specimen being indeterminate. 
The quality of the sponges in the vicinity of their attachment was also injured 
by iron rust. In addition to the sponges planted as described, Doctor Harris 
planted many thousand cuttings by sowing them broadcast over the bottom. 
It is not improbable that some of these may have attached to rocky patches of 
bottom and grown, but if so they became indistinguishable from the natural 
growth, and their history is lost. 



552 



BULLETIN OF THE BUREAU OF FISHERIES. 



In January, 1898, Dr. H. V. Wilson presented before the National Fisheries 
Congress, held at Tampa, Fla., a paper « making some suggestions on rearing 
sponges from the egg and on improving their quality by grafting. In June, 1 907 , 
he published'' some results of his experiments with certain noncommercial 
sponges at the United States Fisheries Laboratory, Beaufort, N. C, demonstrating 
that they could be raised by regeneration from degenerate masses to which the 
sponge is reduced under certain artificial conditions of confinement. Doctor 
Wilson suggested that this phenomenon would probably be presented by the 
sponges of commerce and might be utilized in a system of sponge culture for 
economic purposes. The same investigator has since discovered that practi- 
cally the same effect can be produced by squeezing the soft parts of the sponge 
through bolting cloth into vessels of sea water, the expressed tissue substances, 
aggregating themselves into little heaps on the bottom, eventually regenerating 
the skeletal tissues and developing into complete sponges. None of these 
experiments has been performed on commercial species and the growth of the 
new individuals has not been kept long under observation, but I believe that 
there is no good reason to doubt that it would be possible to apply the methods 
successfully to any of the economic sponges of Florida. 

With the exception of my own investigations and the related and parallel 
experiments of Messrs. Cheyney and Bigelow recounted in the main part of 
this paper, I believe the foregoing to cover all actual experiments in sponge 
culture, save one or two cases in which a very few cuttings or small sponges have 
been planted on the bottom by persons engaged in the industry; but in 1895 
Bidder '^ considered the question from a purely academic standpoint and raised 
certain questions as to the utility of the whole project. Mr. Bidder on a priori 
grounds reached the provisional conclusions, inter alia (i) that the total volume 
of the new sponges grown from cuttings would not exceed the volume of the 
original sponge if it were permitted to attain its natural growth under the same 
conditions for an equal time ; (2) that sponges or cuttings raised above the bottom, 
as in Buccich's experiments, would probably grow more rapidly than the same 
or similar individuals on the bottom; and (3) that the sponge-bearing area, 
naturally confined practically to the bottom, might be extended by using a sus- 
pension system of culture in which several strata between the surface and the 
bottom might be utilized by appropriately constructed supports for the growing 
sponges. How far some of these questions are answered by my own experience 
will be seen in the following pages. 

a Wilson, H. V. : On the feasibility of raising sponges from the egg. Bulletin U. S. Fish Commission, 
vol. XVII, 1897, p. 241-245. 1898. 

b Wilson, H. V. : A new method by which sponges may be artificially reared. vScience, n. s., vol. 
XXV, no. 649, p. 912-915. 1907. 

c Bidder, George: Notes on projects for the improvement of sponge fisheries. Journal of the 
Marine Biological Association of the United Kingdom, vol. iv n. s.) p. 195 -202. 



A PRACTICAL METHOD OF SPONGE CULTURE. 553 

POSSIBLE LINES OF EXPERIMENT. 

Under instructions from the Commissioner of Fish and Fisheries, experi- 
ments in sponge culture were inaugurated in January, 1901, at Sugar Loaf 
Key and at divers places in Biscayne Bay. From the beginning the aim has 
been not to demonstrate purely scientific possibilities, but to develop, if possible, 
a system of sponge culture having present economic application, the condition 
of the fishery being such that there may arise at any time an exigency demand- 
ing immediate measures of relief to the overtaxed natural beds. 

As has been seen from the preceding historical resume, a number of theo- 
retical considerations have been offered by various persons and several attempts 
have been made toward a solution of the problem. It has been proposed to 
multiply and improve sponges by growing them from cuttings, from the egg, 
and from the peculiar degenerative masses described by Wilson, and by grafting 
superior varieties upon those less desirable. Each of these, except the third, 
which has been but recently discovered, was considered when the present 
experiments were begun. 

GRAFTING. 

It does not appear that there is much of value in the suggestion as to 
grafting, which is based upon an imperfect analogy between certain aspects of 
the process of growth in sponges and in the higher plants. Cut surfaces of 
related varieties of sponges, as of related varieties of plants, will fuse and heal 
if brought into proper apposition, but there the analogy ends. In grafted 
plants each member of the union (stock and scion) furnishes essential parts of 
the compound, the stock supplying the roots and trunk of a tree, while the 
scion develops the branches, foHage, and fruit. Without foliage the stock 
would die, and without roots the scion would not survive. In plants, too, 
each member of the graft produces a definite influence on the resultant whole, 
making it more or less unlike either of the pure varieties of which it is com- 
pounded. The fruit produced on the scion will differ from that which is 
produced by the ungrafted stock, while the influence of the latter may be seen 
in greater hardiness, a different size and general habit, or in other respects. 
With sponges the case is quite different. The two members of the union will 
have the same organs and be essentially similar even though they may differ 
in quality and texture. One piece may be attached or rooted, but that is 
immaterial and in a measure accidental, for the so-called root is merely a part 
of the surface adherent to some foreign body and performs no particular func- 
tion other than that of anchorage. If the sponge be torn loose, some other 
part of the surface may with equal facility become the root, or more likely the 
sponge will continue to live and grow as an unattached individual or "roller." 
As has been shown by experiment, if a graft be made, each piece will continue 
to grow independently without influence upon its fellow except in limiting 



554 " BUIvIvETIN OF THE BUREAU OF FISHERIES. 

the direction of its growth, although the character of one or both may be affected 
by any change in environment. A cutting from a sponge transplanted and 
grafted on another growing in a different environment will tend to approach 
the latter in character, not as the result of the graft, but on account of the 
physical surroundings, precisely as it will do if transplanted to the same locality 
without grafting. In other words, nothing can be done by grafting that can 
not be more readily done by propagation from cuttings which attach themselves, 
and the former process results in a waste of time and effort without compen- 
sating advantages. Neither cutting is improved by the amalgamation. Sponges 
of the same species will unite if grafted. Sheepswool sponges from different 
locahties readily fuse, but they will not unite to either yellow or grass sponges, 
and probably not to any species other than their own. 

GROWING FROM EGGS. 

That sponges can be grown from eggs to a marketable size under the 
control which is essential to any system of sponge culture appears probable, 
but it has not yet been demonstrated. Although experiments made with the 
noncommercial sponges show that they can be kept alive for a considerable 
time after development from the egg, I know of no cases in which they have 
been artificially raised to maturity or to any considerable size, and experiments 
with the commercial sponges are still less conclusive. Raising sponges from 
the egg must probably always remain a delicate operation, practicable only to 
skilled investigators provided with special facihties and entirely beyond the 
reach of the practical man engaged in a commercial enterprise. For that 
reason the method appeared to be ill-adapted to the present needs of the sponge 
fishery and was therefore discarded in the experimental work described in the 
present paper. As has been pointed out, however, in an academic discussion 
of the proposition by H. V. Wilson, it may be that this method will have a 
distinct place in the sponge culture of the future, though its development and 
practice must probably necessarily be in the hands of a few skilled operators. 
It may be possible to breed sponges from selected parents, thus improving 
their quality and supplying better seed sponges from which to make cuttings. 
Possibly some system of hybridization may be developed along lines analogous 
to those which have produced such astounding results in the hands of experi- 
mental horticulturists. 

The plasticity of sponges and their extreme susceptibility to environmental 
influence, as well as the technical difficulties which the experimenter must over- 
come in his attempts at breeding and hybridization, will probably long postpone, 
if they do not entirely defeat, successful efforts in this direction. The problem 
is one which may well be taken up and studied when the Bureau of Fisheries 
comes into possession of a properly equipped laboratory in the sponge region 
of Florida. 



A PRACTICAL METHOD OF SPONGE CULTURE. 555 

GROWING FROM DEGENERATIVE BODIES AND TEASED OR DISSOCIATED TISSUES. 

Wilson's extremely interesting and scientifically important studies in this 
field open, as he points out, a new means by which sponges may be propagated. 
The experiments so far have been confined to noncommercial species, but there 
appears to be no reason for believing that they can not be applied to horny 
sponges. In fact, in certain "sick" sheepswool sponges in my experimental 
plants I have observed in the dead skeletal remains certain degenerative masses 
resembling, at least superficially, those described by Wilson in silicious sponges. 

Wilson's methods are to induce the partial death of the sponge and the 
production of small degenerate bodies in the remaining living tissue, or to tease 
up the soft tissue, or finely divide it by squeezing it through bolting cloth bags. 
The resulting small masses speedily attach and regenerate into little sponges. 

Leaving out of consideration the morphological significance of these 
processes, and viewing them solely from the practical standpoint of sponge cul- 
ture, these methods of rearing sponges appear to be essentially similar to rearing 
from cuttings made with a knife, the main difference being that the tissue aggre- 
gates, or pieces, are obtained by an elaborate method instead of a simple one. 

GROWING FROM CUTTINGS. 

This method was adopted as that giving greatest promise of success, and 
it is discussed in detail in the following chapters. 

PROPAGATION OF SPONGES FROM CUTTINGS. 

Growing sponges from cuttings has to recommend it, as a practical method, 
its simplicity and the certainty with which the excised pieces will attach and 
regenerate when placed under suitable conditions. The ease with which suitable 
seed sponges may be obtained at any season, their immunity from the effects of 
more or less rough handling, the facility and rapidity with which they can be 
attached to such materials as may be selected, the promptness with which they 
will grow fast to suitable foreign bodies, and the certainty with which they heal 
and grow into perfect sponges make this an immediately feasible method of 
sponge culture, provided the proper means of attachment and methods of han- 
dling can be developed. How far the present experiments have solved the prob- 
lems will be seen in the following account. 

SEED SPONGES. 

For seed any healthy sponge may be used, whatever its shape or size. Torn 
and irregular specimens, or those so filled with sand and other foreign matter as 
to make them of httle value in the markets, may be utilized equally with well- 
shaped ones, though they often do not cut so economically in respect to either 
material or time. When the seed sponge is heavily loaded with shells, corals, 



556 BULLETIN OF THE BUREAU OF FISHERIES. 

and similar material, there is always considerable waste and much time is lost 
through the dulling of knives and the necessity of avoiding obstacles too stout to 
cut. For this reason it is economy to select the cleaner specimens for seed when 
they can be readily obtained. The sponges as fast as detached from the bottom 
should be placed in a gunny sack or net attached to the side of the boat or, if 
taken by diving, carried by the diver, the sack when full being emptied into a 
live car. During cool or moderately warm w^eather, treated thus, they will re- 
main alive and uninjured for several weeks, though if the sea be rough their sur- 
faces are likely to become more or less abraded by rubbing against the sides of 
the car. They must not be brought into water at all brackish, however, or they 
will be speedily killed. In warm weather if long confined even in salt water 
some will sicken and die, and the resulting foul Avater will soon produce a general 
epidemic. 

In carrving live sponges from the beds to the planting grounds a boat- 
shaped or spindle-shaped live car will be found most convenient, as either can 
be towed rapidly and for long distances without injuring the contents. The 
car should be provided with several "thwart-ship" bulkheads or partitions 
dividing it into compartments, and the slits or perforations in the forward end 
should be small or narrow so as to reduce the violence of the currents set up 
by its rapid passage through the water. If these openings be large, the sponges 
will churn violently or be massed under pressure at the after ends of the com- 
partments and are certain to be more or less injured. The car preferably 
should be constructed entirely of wooden slats and boards, as wire netting 
tends to abrade and injure the surfaces of the sponges. Where a boat with a 
small "well" is available, sponges can be transported in that, or when the 
distance is short they may be carried in tubs of water protected from the sun 
b)- cloths or sacks, but they should be removed from the tubs and placed in 
open water as soon as opportunity occurs. In cool weather they can be readily 
carried for many hours without water if they are protected from the sun and 
rain and kept moist with sea water. At the planting grounds the sponges 
may be kept best and most conveniently by stringing them on rope yarns about 
5 or 6 feet long, the two ends of which are then tied to stout lines or wires 
stretched between stakes so that the sponges are suspended just clear of the 
bottom. In a situation where the water is sufficiently salt and pure they will 
readily live longer than the lines will last, and at the same time they will be 
easily accessible, those required from time to time being conveniently detached 
without disturbing the remainder. 

There is some reason to believe, as is discussed later, that in regions which 
have been for years subject to an intense fishery, especially where the water is 
shallow and generally clear, a race of slow-growing small sponges may be devel- 
oped by constantly selecting out the larger more rapidly growing specimens, 



A PRACTICAL METHOD OF SPONGE CULTURE. 557 

and that cuttings made from such seed will not grow as rapidly as those from 
more virile stock. When there is reason to suspect this, seed should be brought 
from other localities. 

CUTTINGS. 

In the beginning of the present experiments the cuttings used were small, 
about I by I by I yi inches, the purpose being to secure as many plants as possible 
from a given quantity of seed sponges. This size gives from loo to 120 plants 
from a 6-inch sponge. Theoretically the use of small cuttings was correct for 
securing the greatest ultimate product from a given amount of material. As 
is shown hereafter, the average growth in diameter is fairly constant for the 
first four years at least, and the relative increase in volume or weight is there- 
fore greatest when the cuttings are small. Growing at the average rate of i 
inch per year, 120 cuttings made from a 6-inch sponge would in four years 
reach a volume of about 75 times that of the original sponge, provided there 
was no mortalit}-, whereas the same sponge cut into 20 pieces, in the same time 
and under the same conditions, would increase about 20 times, while if the seed 
sponge were planted entire it would increase but 4 or 5 times, provided it grew 
at the average rate established for specimens up to 8 inches in diameter. This 
is illustrated in principle, though not in detail, in figure 6, page 575. The solid 
line shows graphically the growth of an entire sponge, the middle dotted line the 
aggregate increase in a sponge of the same size cut into 20 pieces and the upper 
line the increase when cut into 50 pieces, in each of the latter two allow- 
ance being made for a mortality of 5 per cent of the cuttings per annum. 

It was found, however, that the smaller pieces were placed at considerable 
disadvantage by reason of the greater readjustments required to perfect again 
the canal system, and moreover when they were injured, as frequently happens, 
a proportionately larger part of their substance was affected and the regenera- 
tion required to convert the fragments into functionally and anatomically per- 
fect sponges was more drastic. These two factors operated to produce a some- 
what higher mortality in the small cuttings than in larger ones, and moreover 
tended to retard materially the growth of the first six months, though after 
that there was little difference between the diametric increase of large and 
small pieces. The smaller cuttings also require a longer time to reach a market- 
able size, the planter has to wait longer for his returns, and in the meantime 
the sponges are subject to such risk of disaster as may exist. In properly 
selected localities the last consideration is not very grave. It was necessary, 
therefore, to effect a compromise between the theoretically economic advantage 
of employing small cuttings and the practical biological superiority of large 
ones, and it was finally established that pieces about i>< by 2>^ by 3 inches 



558 BULLETIN OF THE BUREAU OF FISHERIES. 

(pi. LXix) or of approximately the same volume, were the best, all things con- 
sidered. The shape of the cuttings will, of course, vary with the size and shape 
of the seed sponge, but the more nearly equilateral they can be made, the more 
generally satisfactory they will prove. Thin edges or ragged parts are likely to 
die and slough off. 

In making the cuttings it is generally better first to cut away the roots of 
the seed sponges if they contain fragments of rock or coral or shells. Otherwise 
much time is lost through the dulling of the knives. For this rough work it is 
well to use a heavy knife with its edge serrated by vertically grooving the fiat 
face of the blade with a three-cornered file, converting it into practically a 
sharp-edged saw. For making the actual cuttings large butcher knives of good 
quality should be employed, and they should be kept sharp by frequent whetting 
with a coarse stone, such as is used for sharpening scythes. A rather rough 
ragged edge is preferable to a smooth one. If the knife be in proper condition 
the sponges will cut as readily as beef liver, but if it be dull the operation is 
slower and the cuttings are liable to injury by the compression of their tissues 
under the knife. 

The direction of the cuts will depend upon the size and shape of the seed 
sponge, but in the majority of cases the latter should be placed on a wet board, 
root down, and cut into slices from i% to i>^ inches thick, each of these being 
subdivided to best advantage as dictated by the judgment of the operator. 
It is desirable, but not essential, to leave on each cutting one surface covered by 
the uninjured skin of the original sponge. I have successfully grown cuttings 
taken from the interior of the sponge, but while the mortality is no higher and a 
new skin is soon formed over the entire surface, growth appears to be somewhat 
more slowly initiated than in the case of normal cuttings. 

Neither the seed sponge nor the cuttings are injured by moderate exposure 
to the air, but it is safer, especially in hot weather, to throw the pieces into a 
tub of fresh sea water as soon as cut. Care should be exercised to change the 
water at intervals of about one hour, as the cuttings will be injured and probably 
die if left for any length of time in foul water and a few fragments of dead 
sponge will speedily contaminate a tubful. Neither the entire sponge nor the 
cuttings should ever be brought into water much below oceanic saltness and 
care should always be taken to protect the tubs from rainfall, which appears to 
have an effect disastrously out of proportion to its volume. If it is necessary to 
keep cuttings over night they should be placed in netting bags and hung in the 
open water, but they should never be so left more than a day or two, as they 
will soon grow together and be separable without injury only by the knife. Speci- 
mens left in contact for three or four days have grown into conglomerate masses 
difficult to handle. 



A PRACTICAL METHOD OF SPONGE CULTURE. ^ 559 

ATTACHMENTS. 

The chief problem confronting the experimenter in sponge culture is to 
find some ready and economical means of attaching the cuttings to a durable 
support which shall be capable of resisting the chemical action of sea water 
and the ravages of the teredo and other animals having similar destructive 
habits, and which at the same time is without injurious effect upon the 
sponges. During the course of the present experiments numerous materials 
and methods were employed, most of which sooner or later demonstrated their 
unfitness to fill the requirements. It was found that the cuttings would speedily 
attach to any firm, clean, innocuous material, and many methods of attach- 
ment appeared satisfactory for a year or two, but then developed some defect 
due to corrosion, tensile weakness, or the lack of sufficient attaching surface. 
It was necessary to await developments before the direction of further ex- 
periments was indicated, and much time was expended on materials which 
afterwards developed unexpected defects. 

During the first season the cuttings were attached to stakes and rectangular 
frames laid on the bottom, to vertical stakes, and to pieces of coral rock and 
small copper wires laid on the bottom. Some of the sponges were threaded on 
the supporting copper wires and others were bound to them by means of short 
pieces of lighter wire, with the expectation that the sponge would eventually 
encompass its support. About six weeks after the plants were made it was 
found that 95 per cent had healed and were living under apparently healthy 
conditions, but seven or eight months later most of them had died. It was 
expected that the action of the sea water on the copper wires would produce 
poisonous salts, but in quantities so small as to have merely a local effect. 
It was found, however, that wires one-sixteenth inch in diameter were com- 
pletely corroded away in places, especially where the cuttings were attached, 
and the latter were either killed, or lost by the breaking of the wires. The 
effects were especially pronounced when the wires v/ere lying on the bottom. 
The cuttings placed on the bottom on rocks and stakes soon became covered 
with silt and vegetable growths and were either killed or lost, and it was evident 
that the choice of both materials and localities had been unfortunate. 

During the winter of 1 901-2 advantage was taken of the experience gained 
during the preceding year, and in addition to Biscayne Bay and Sugar Loaf 
Key, where the first year's experiments were made, Anclote Key was selected 
as an additional locahty. Instead of using naked copper wires, various types 
of insulation were tried, other metals, including lead and heavily galvanized 
iron, and various cordage materials were experimented with, and molded forms 
of terra cotta, plaster, and cement were used in place of the rocks and stakes 
placed on the bottom. The more or less expensive insulations composed of 



560 BULLETIN OF THE BUREAU OF FISHERIES. 

various patented compounds of rubber, etc., which have been found to possess 
superior properties for electrical purposes, soon developed their worthlessness 
for sponge culture, the insulation being affected by salt water and stripping 
from the wires. Underwriters' insulation, so called, a cheap covering of cotton 
and white lead, proved to be more durable and lasted for upward of two years, 
but it, too, eventually stripped or crumbled from the wire. Ordinary telegraph 
wire electrolytically galvanized rusts very quickly and breaks into pieces. 
Iron wire galvanized by the "hot process" will last for a number of years if 
kept fully immersed in sea water, but when it is periodically partly exposed 
at low water it rusts more quickly, and moreover the zinc coating kills that 
part of the cuttings brought into contact with it. Iron wire coated with lead is 
also quickly destroyed, and copper wire coated in the same way kills the sponges. 
Plain or "black" iron rusts quickly and breaks, and the iron salts are injurious 
to the fiber of the sponges. Aluminum wire is innocuous as to its salts in sea 
water, but is rather expensive when of sufficient diameter, and is subject to 
rapid corrosion in spots, causing it to break into pieces. 

Asbestos cord was found to be practically indestructible chemically, but 
when wet the fibers become loose and frayed and so slippery that the tensile 
strength is seriously reduced. This difficulty was overcome by treating the cord 
with rubber solutions, white lead, a mixture of paraffin and asphaltum and 
other waterproofing and cementing substances. This treatment very greatly 
increases the strength of the cord, especially in the water, but the rubber is 
somewhat expensive and the asphaltum, despite its mixture with paraffin, has 
an abrasive effect on the cuttings and Avears large holes where the cord passes 
through the growing sponge. 

Jute, sisal, manila, cotton, and hemp lines were employed, but as expected, 
they were all quickly destroyed in salt water. Coir (cocoanut fiber) rope was 
not experimented with, as there was some difficulty in obtaining it, and more- 
over, experiments with the fiber showed that it, too, is more or less quickly 
rotted in the water. 

Stakes and other wooden structures placed on the bottom are quickly 
riddled by the teredo and other boring organisms. If planted green with the 
bark on they will last longer, but the bark of the most durable, the mangrove, 
has a bad effect on the sponges, while that of other trees tends to scale off after 
a while, the sponges becoming detached with it. If there were no better method 
available, black mangrove and white wood stakes stripped of bark would prob- 
ably hold together for four years, but to prevent rotation and capsizing they 
must be nailed together in frames. 

To none of these materials, excepting the barked stakes, did the cuttings 
make organic attachment. When the artificial attachments loosened, the 
cuttings were free to rotate and drift on the wire, and when the latter was at 



A PRACTICAL METHOD OF SPONGE CULTURE. 56 1 

all rough, holes of considerable size were eroded in the sponge. Asbestos cord 
treated with rubber solution was least objectionable in this respect, owing to 
the softness of its surface and the firmness with which it could be gripped by 
the binding wires, the method of applying which is explained later. 

It was found that this difficulty of the corroding wires was obviated by the 
use of lead wire, to which the cuttings speedily form organic attachment and 
cling independently of artificial aid. The tensile strength of this metal is so 
low, however, that in spans it will not support itself, to say nothing of the 
weight of the sponges and the pressures exerted by waves and currents. To 
secure the virtues of lead, its freedom from corrosion, its chemically inert and 
innocuous quahties, and the facility with which the cuttings grow fast to it, 
while at the same time eliminating its defect of tensile weakness, the device was 
adopted of employing a strong fiber or wire core encased in a thin coating 
of lead. 

Several types of this construction have been employed with varying success. 
One of the earliest was ordinary tarred marline encased in lead about one thirty- 
second inch thick. This was light and when new quite strong enough for the 
purpose, but eventually the marline rotted and the lines broke, though some 
lasted for two years. Asbestos cord covered in the same way was also experi- 
mented with and found unsatisfactory. 

Several forms of lead-covered insulated wires have been used, but the ordinary 
commercial sorts have been unsatisfactory, being either too heavy and expen- 
sive, or, if sufficiently light and cheap, lacking in durability. Commercial under- 
writers' wire with a copper core and specially encased in lead was superior to the 
higher priced insulations, and a still better wire was of the same type with the 
copper core replaced by galvanized iron. This had to be made to order, as there 
are no such insulated iron wires on the market. 

All of these wires and lines were used in the same general way, stakes being 
driven in the bottom in parallel rows at intervals of about 25 feet and the wires 
suspended between to form squares. At first the wires were attached merely by 
tying or winding them about the stakes, but it was found that this rigid attach- 
ment caused them to break under the repeated flexure to which they were sub- 
jected by swaying in the waves. Later galvanized rings were placed over the 
stakes, four wires radiating at right angles from each toward the adjacent stakes, 
the whole being supported at a proper height above the bottom by means of a 
short wire attached to the stake and ring, respectively. 

When lead-covered lines began to be employed they could not be attached 
directly to the rings on account of electrolysis, which would cause the iron to 
rust, and the rings were then wrapped with insulating tape to keep the two 
metals from coming in contact. Here another difficulty was encountered, the 
lead coating wearing through when loosely attached to the ring, or breaking near 



562 



BULLETIN OF THE BUREAU OF FISHERIES. 



the ring under repeated flexure when rigidly attached. In the latter case the 
insulation was abraded by the rubbing of the rough edges of the broken lead 
casing, and the exposed core broke by the concentration of flexure at the 
weakened point, or else, coming into contact with the lead, was destroyed by 
electrolysis. 

To overcome this, horseshoe-shaped porcelain pieces were interposed 
between the rings and the wires, as shown in figures i and 2. By this means 
the electrically antagonistic metals were kept apart and at the same time there 





Fig. I Axi> 2. — Showing insulated attachment for lead-covered hnes supporting sponge cuttings. 

was formed a rocking attachment without wear on the lead, the flexure of the 
wire being distributed throughout its length instead of being concentrated near 
the stakes. 

With galvanized iron wire with underwriters' insulation and incased in lead, 
this device served very well so long as the sponges were not much over 4 inches 
in diameter, but when they grew larger there was a contingency which had not 
been anticipated, the sponges being torn loose and rotating on the wire. Practi- 
cahy all of the wires used were less than one-fourth inch in diameter, a larger 
size being objectionable on account of its weight and the hole produced in the 



A PRACTICAL METHOD OF SPONGE CULTURE. 563 

Sponge. This gave a small surface of attachment which, while sufficient at first, 
became proportionally smaller as the sponge grew. The attached area, and con- 
sequently the strength of the attachment, grew proportionately to the diameter 
of the sponge, while the forces acting to loosen it grew in proportion to the surface 
exposed to the impact of the waves. The consequence was that in rough water 
sponges 5 inches in diameter were generally torn loose, and, once started to 
rotate or oscillate, a large hole was soon worn about the wire to the detriment of 
the quality of the sponge and the retardation of its growth. In sheltered places 
sponges were successfully grown on wires until they reached a diameter of 7 
inches, but eventually they also must have become loose. 

To correct this tendency to loosen, the shape of the wire was modified to 
assist the strength of the attachment by mechanical resistance to the rotation of 
the sponge, longitudinal slipping on the wire being negligible after the attach- 
ment of the cutting is once established. A galvanized iron ribbon three-eighths 
inch wide and one-sixteenth inch thick was incased in a tight-fitting lead jacket 
one thirty-second inch thick, the whole making a flat band one-eighth inch thick 
and not quite one-half inch in breadth. This appears satisfactorily to prevent 
rotation in sponges as large as 8 inches in diameter. 

This lead-incased ribbon is durable so long as the casing is not mechanically 
broken or punctured. At the cut ends the iron rusts away slowly, but the con- 
tact between the iron and the lead is so intimate that the water at a depth of 
10 or 12 feet penetrates but an inch or two at most, and electrolysis is, therefore, 
strictly localized to the open ends. It has to be handled with care, however, as 
the thin lead is easily punctured and the sHghtest hole becomes the seat of electro- 
lytic action to the speedy destruction of the iron and the consequent breakage 
of the ribbon. When carefully put out this material has lasted for three years 
with no other sign of impairment than the rusting away of about one-half inch 
of the iron where exposed at the ends. Its strength is great, as was demonstrated 
at Biscayne Bay during the great hurricane of 1906 when a piece of wreckage 
fouled some of it, pulling up deeply embedded stakes and flattening a %-inch 
wrought-iron ring without injuring the ribbon. It is heavy and difficult to 
handle when planting from a small boat and there is also some difficulty in 
attaching it at the stakes. It, of course, can be bent in but one plane, and it 
can not be attached directly to the rings owing both to the electrolytic effect upon 
the latter and to the abrasion of the lead casing of the ribbon. 

In the experimental work porcelain insulators were attached to the rings 
by means of galvanized wire, the ribbon being bent over them, with a piece of 
thin sheet lead interposed, and secured by means of a flattened seine lead or 
piece of lead piping as shown in figure 2. In a commercial application a 
special insulator similar in general shape to that shown in figure i could be 
employed. In any case it is necessary to place a piece of sheet lead or asbestos 



564 BULLETIN OF THE BUREAU OF FISHERIES. 

cloth between the porcelain and the ribbon to prevent wear and tear on the 
lead covering of the latter. 

All of the foregoing experiments were made with a view to the utilization 
of soft muddy or grassy bottom upon which sponges will not grow naturally 
and in depths not exceeding 10 or 12 feet. This would have made possible the 
utilization of considerable areas among the keys and close to shore along the 
Gulf coast, in localities where the plantations could be readily protected. The 
results of the work, however, have failed to disclose a material which is satis- 
factory in all respects. The lead-covered iron ribbon if carefully handled and 
planted with its casing uninjured has sufficient durability and prevents the 
loosening of the sponges as they reach commercial size, but it is not a com- 
mercial product and has to be made to order, which militates against its use 
by small planters, while its weight makes it somewhat difficult to handle in 
lengths of more than 15 feet, this, in its turn, increasing the cost of stakes, 
rings, and attachments. The rings and insulators will last indefinitely, the 
stakes will have to be renewed once during the growth of the sponges, and the 
indications are that the ribbon, or at least most of it, will not be useful for a 
second planting. Lead-incased galvanized-iron underwriters' wire about one- 
fourth inch in external diameter with no. 12 Brown & Sharp gauge core is 
durable, costs about one-half as much as the ribbon, is easily handled, and 
much of it can be used for a second planting, but on account of its circular 
cross section the sponges as they grow will loosen and rotate in any but the 
most sheltered places. 

The value of a method which would permit of the utilization of otherwise 
useless and barren bottom in shoal water is great and w^arrants further experi- 
ment, but the results so far obtained are not such as would justify the recom- 
mendation of any of the methods or materials experimented with. The experi- 
mental results of the work with wires are valuable on account of the facility 
with w^iich the sponges could be examined and the data which it has been 
possible to obtain as to the rate of growth, the mortality, and the general behavior 
of the cuttings. 

As has been mentioned, in the very beginning of the work experiments 
were made with various bottom attachments. The use of stakes or poles has 
already been discussed and the objections stated. They never offered much 
encouragement for further trial. The plaster, cement, and pottery forms first 
employed w^ere about 5 inches in diameter on the bottom, 4 inches on top, and 
about I >^ inches thick. The larger face was slightly convex, and the smaller, 
to which the cutting was attached by means of a V-shaped wire running through 
a central hole, was flat. They were found to be too small, tending to capsize 
as the sponges grew and offering greater surface to the impact of waves and 
currents, and there was also some difficulty with silt and vegetable growths which 



A PRACTICAL METHOD OF SPONGE CULTURE. 565 

interfered with the welfare of the cuttings so that they were also difficult to 
keep under observation for experimental purposes. 

Owing to the encouraging early results and the apparent advantages of 
the wire suspension methods previously described, provided a suitable material 
could be obtained, work with bottom planting was suspended for several years 
but was taken up again in 1905 when it became apparent that none of the lines 
and wires previously experimented with was likely to prove satisfactory. About 
the same time a sudden disaster, due to the presence of drainage water near 
the surface on the plantation at Anclote key, made it necessary to transplant 
hurriedly the remaining sponggs to the bottom in another locality. Not only 
the plantation of the Bureau of Fisheries was affected, but also that of Messrs. 
Cheyney and Bigelow, v/ho on an adjoining site had been, for two years pre- 
ceding, conducting a similar experiment on a commercial scale. 

Bricks, rocks, and anything available were first used in the hurry to remove 
the sponges from untoward influences, but in the meantime there were being 
made a number of cement disks larger and heavier than those used during the 
first two years of the experiment. These disks (pi. lxviii) are about 10 inches in 
diameter and i^^ inches thick, and are composed of a mixture of i part cement 
to 3 or 4 parts sand. They are molded in iron rings of the required dimensions 
laid on the sand, and two holes about 4 inches apart are made in each by thrusting 
through the cement before it hardens an iron bar three-eighths inch in diameter. 
The molds are removed as soon as the cement has set and before it hardens, 
the operation being facilitated by running a thin-bladed knife around the inside 
of the rings to break their adhesion to the disk. The disks can be made by 
this method for less than 2 cents each, including material and labor. 

For experimental work hollow triangles (pi. Lxvii) were substituted for the 
disks, six sponges being planted on each. As each triangle was marked or num- 
bered, record could be kept of the growth and behavior of the cuttings, and as 
the large triangles were less easily overlooked than the smaller disks and as each 
was planted with a definite uniform number of cuttings, the rate of mortality 
could be readily determined from time to time. 

These disks and triangles are satisfactory on rocky bottom, but tend to bury 
on sand, marl, or soft mud. They may, however, be used on bottom with a 
sparse growth of grass. When the grass is long and dense it tends to fall over 
the sponges, causing death or irregular growth. Where shifting sands and silt 
are carried by the currents these materials tend to deposit in the eddies on the 
lee side of the disks and triangles, and eventually pile up around the base of the 
sponges and kill them. To obviate this difficulty spindles were placed in some of 
the triangles (pi. lxvii) and disks, six in each of the former and one in the latter, 
the cuttings being attached near their tops so as to prevent free flow of the currents 
beneath. These spindles project about 8 inches and various materials were tried. 



566 BULLETIN OF THE BUREAU OF FISHERIES. 

the most satisfactory being short lengths of the lead-covered iron ribbon before 
described. They serve the purpose perfectly, they are sufficiently durable, the 
sponges soon permanently attach, and no suffocation occurs in places where cut- 
tings on the disks would be buried in mud or sand. The spindles are, however, 
about double the cost of the disks, and although the indications are that if care- 
fully handled they will last long enough to mature two crops of sponges, they 
eventually will be destroyed while the disks are practically indestructible. The 
spindles also prevent close packing of the disks and are more troublesome to 
handle, but on the other hand they facilitate the attachment of the cutting, as 
will be hereafter explained. 

PLANTING. 

The method of applying the cutting to the support has undergone gradual 
modification. In the early experiments with various insulated wires, when the 
sponge did not form organic attachment, the pieces were bound against the sup- 
porting line with short pieces of aluminum wire thrust through the sponge and 
twisted around the support. It was found that the cuttings were often slow in 
growing around the support and should the binding wires become loose were 
likely to be detached and lost. To obviate this difficulty the expedient was 
adopted of slitting the cutting, placing the two legs of the slit astride of the sup- 
porting wire and binding the several faces in close apposition by means of rubber 
bands or short aluminum wires traversing the two flaps of the cutting and at 
their ends twisted around the supporting wire. Under such conditions the 
slit speedily fused and the cutting became organically intact about the wire. 
Aluminum was employed for binding because its salts in sea water are neither 
rapidly produced nor injurious. 

With the use of lead-covered materials, to which the sponges grow fast, it 
became possible to "thread" the cuttings on the wire, the use of binding wires 
being unnecessary to hold them in position. To facilitate this operation needles 
(text fig. 3) were made of clock-spring steel, one end being shaped to a sharp 
stiletto point, and the other rolled or folded over to form a socket fitting the end 
of the wire on which the sponges were to be planted. In planting, the needle 
was fitted to the wire and the cutting pierced by the sharp end of the needle and 
pushed onto the wire as one would use an ordinary needle and thread in stringing 
beads. After attaching the ends of the wires to the stakes the cuttings were 
distributed at regular intervals by sliding them along with the hand, their fric- 
tion against the lead usually holding them in place until organic attachment 
occurred. Several mechanical distributers were devised and experimented 
with, but none was very satisfactory. 

In planting on plain disks the cuttings are pierced by short aluminum wires, 
the ends of which are carried through the two holes already described and twisted 



BuL. U. S. B. F., 1 90S. 



Platr I.XVIII. 





A PRACTlCAIv METHOD OF SPONGE CULTURE. 



567 



A 



on the under side (pi. ivXViii, fig. 2). This is a rather slow process, and it is not 

possible for two men to cut, attach, and plant more than about 100 cuttings per 

hour. To accelerate the speed of planting I have placed in the center of each 

disk a short spindle of j4-'mch. lead wire, slightly flattened at the top by a blow 

from a hammer and projecting to a length of about 2}4 inches (pi. ivXViii, fig. i). 

About 8 or 10 cuttings are placed on a long needle (fig. 3) of the required 

shape, the socket of which is placed upon spindle after spindle in succession and 

the cuttings pushed into place in contact with the 

cement base, each with a single motion of the left 

hand. Friction of the slightly stretched tissues 

against the spindle and the burr at the top of the 

latter prevent the detachment of the cutting, which 

in a few days grows fast to both the spindle and the 

disk. With this device two men can plant from 250 

to 300 cuttings per hour, and this gain in speed over 

the other method is highly important in places where 

rough weather is prevalent, as it makes possible the 

fullest utilization of such opportunities as present 

themselves. The spindles add about 25 per cent to 

the cost of the plain disks, but as they will survive 

a number of plantings this cost is compensated for 

by the decreased cost of labor. 

This system also facilitates replanting with cut- 
tings at the time of harvesting of the first crop, as 
the grown sponges can be quickly detached and 
new cuttings substituted. In shoal water where the 
sponges can be taken with hooks, two additional men 
in the boat should be ample to detach the sponges 
and replant the disks as rapidly as they are brought 
up. In deep water where a diver has to be em- 
ployed for harvesting the crop, the cuttings can be 
taken down by the diver and planted as the matured 
sponges are removed, avoiding the labor and incon- 
venience of bringing the disks to the surface, and reducing the cost of opera- 
tion very much more than sufficient to cover the increased first cost of the 
disks. 

The expense of labor in deep-water planting is of such importance that the 
strictest economy of operation, especially in taking up the sponges, must be 
given careful consideration. The diver's time must be economized, as the 
time of the entire crew of the diving boat is dependent upon the rapidity and 



CLD 



O 



3. — Needles used for threading 
cuttings on supporting wires. 



568 BUIvIvETlN OF THE BUREAU OF FISHERIES. 

efficiency with which he works. The attachment of sponges to the disks by 
means of wires is slow under the best conditions and must be much slower 
under water where work is done at a disadvantage, but the cuttings can be 
slipped on to the spindles as readily under w^ater as in the air. 

The same considerations apply to cuttings planted on long spindles (pi. lxvii) 
which will hold them above the bottom and in deep water. Especially in a 
locality requiring the transport of the disks or triangles for considerable dis- 
tances, the second planting can be carried on more economically than the first. 
Holes should be punched in the disks, however, even when spindles are used, 
so that a wire attachment can be employed should the spindle eventually be 
broken off. 

The density with which sponges can be planted on the bottom in any 
given locality is a subject which will require actual experiment on a commercial 
scale for its elucidation. That ordinary waters will support a dense growth of 
miscellaneous sponges is well known, and among the Florida keys I have 
observed an average of several to a square yard over considerable areas. 

Though nothing is known of the actual facts concerning the food of sponges, 
it can hardly be doubted that all horny sponges feed on essentially similar 
material. If this be true, it is fair to assume that an area which will support 
a large number of useless horny sponges should support and produce an equal 
volume of the commercial kinds. Unfortunately the shoal-water beds of our 
coast are now so depleted that present day observ^ations are useless and the 
distribution of the valuable kinds on the deep water grounds is so unequal, 
owing to the irregular and sporadic occurrence of suitable bottom, that nothing 
definite can be learned. I am informed by Dr. H. M. Smith, however, that 
in very shoal waters in the Philippine Islands he has seen commercial sponges 
somewhat similar to the Florida grass sponge averaging one to every square 
foot of the bottom over areas many acres in extent. The commercial experi- 
ment carried on at Anclote Key by Messrs. Cheyney and Bigelow showed that, 
even in an unfortunately selected locality, cuttings would grow rapidly when 
planted with a density of about one per square yard over an area of about 15 
acres, and that the gro\vth was no less satisfactory than upon the government's 
neighboring plantation covering but a few acres. In no case, on any of the 
plantations under observation, did the density of planting, up to a maximum 
of a little over one sponge per square yard, have any apparent effect upon the 
rate of growth. In bottom planting on a small scale sponges have been planted 
in some cases as densely as 5 or 6 per square yard without apparent bad effect, 
but with extensive areas so thickly planted it is possible that there might be 
an insufficiency of food. Experiments in Biscayne Bay appear to indicate that 
sponges grow more rapidly in strong currents, and presumably the same con- 
dition would permit denser planting than where the currents are weak. 



A PRACTICAL METHOD OF SPONGE CULTURE. 569 

RATE OF GROWTH. 
(Plates Lxix to lxxvi.) 

The rate of growth of cuttings is a matter of paramount practical impor- 
tance to the prospective sponge cuhurist, and it has been the subject of con- 
siderable discussion and difference of opinion. The fishermen variously claim 
that on the natural beds sponges grow to a "marketable size," presumably 6 
or 7 inches in diameter, in from six months to a year, basing their statements 
on the fact that grounds supposedly denuded one year are found to bear salable 
sponges the next. They fail to consider the certainty that they have over- 
looked a number of large specimens and numerous small ones already well on 
their way to merchantable size. Smith, in his paper, "The Florida Com- 
mercial Sponges," basing his statement upon the reports of others, says that 
the claims of the spongers are borne out by experiments, and that "in as short 
a time as one year, under favorable conditions, the cuttings will attain a mar- 
ketable size, and certainly within sixteen or eighteen months the harvesting of 
relatively large sponges may be depended on." To substantiate the statement 
he furnishes a photograph, a careful inspection of which creates the impression 
that the photographer has somewhat assisted nature in establishing the apparent 
rate of growth. I have reason to believe that both Dr. Harris, the grower 
of the sponges in question, and Dr. Smith were deceived as to both the age 
and the origin of the larger specimen, and that it came from a mangrove root 
and not from a wire, as supposed. As photographed it is about 5K inches in 
diameter and is said to be not over eight months old, but I have seen a number 
of other sponges planted at the same time and place and under the same con- 
ditions which had attained a size of not over 4 inches when between three and 
five years old. They were all planted under unfavorable conditions, and the best 
result that I have been able to attain in the same locality and under better 
conditions of growth was an equal diameter in about two years from cuttings 
between 2 and 2>^ inches cube. 

The experiments by Fogarty at Key West about 1880 have not been accu- 
rately or definitely reported, but it is said that cuttings about 2j< inches in 
diameter in some cases increased from four to six times in bulk within a period of 
six months. This is more in accord with my own experience, though, as will be 
shown later, the relative increase in volume is greater with small cuttings than 
with larger ones. 

The results obtained by Buccich are also out of accord with the popular 
view of the rate of growth of sponges under natural conditions, although the 
reports of his work are lacking in definiteness. His cuttings, about i inch cube, 
increased to two or three times their original bulk in one year and did not reach 
full marketable size, the exact dimensions not being stated, until the lapse of 
seven years, a much slower rate of gro\\^h than in Florida. 



570 BUIvLETiN OF THE BUREAU OF FISHERIES. 

My own experiments show that the raw surfaces of cuttings become pig- 
mented within a few days and that at the end of a month they have completely 
healed and have begun to grow and project little papilla or cones. Sharp angles 
and edges generally die and slough off slightly, and the central portions of the 
plane faces become swollen so that at the end of three months in small cuttings 
and somewhat later in larger ones there is evident a distinct teiidency to ro- 
tundity. At the end of six months in many specimens the cut faces can not 
be distinguished from the original surface of the sponge and in practically none 
can they be determined except by the shape. In all cases there is a constant 
tendency toward a spheroidal or ellipsoidal shape, cubical cuttings approaching 
the former and irregular ones the latter form if suspended above the bottom, 
but all becoming cake-shaped if grown from basal attachments. (Compare 
plates Lxxiv and lxxv.) 

Growth takes place in all directions with approximate equality when the 
cuttings are suspended freely in the water, but is generally more rapid in the 
horizontal plane when the sponge is attached to a basal support. If the cutting 
be attached to a small horizontal surface it will grow downward over the edges, 
and if the surface be uneven it will project itself into all the irregularities and 
holes. For this reason, if basal attachments are used, it is desirable to have them 
with smooth surfaces and of a horizontal expanse greater than that of the sponges 
which it is desired to grow, otherwise considerable weight, and also time, is 
lost in trimming the marketable specimens to a desirable and uniform shape. 

Buccich observed considerable variation in the rate of growth and my own 
experiments confirm his statements. Cuttings which, so far as could be deter- 
mined, were similar in size, shape, and character, diverged widely from one 
another in this respect and some of them, while healing completely and remain- 
ing in an apparently healthy state, had grown hardly at all in the course of 
several years. In some cases cuttings made from the same sponge exhibited 
this diversity. Different lots of cuttings of the same average size and planted 
in the same locality exhibited a remarkably uniform average rate of growth year 
after year. In Sugar Loaf Sound the average annual increase in diameter was 
about 0.8 inch, while at Anclote Keys and Cape Florida it was from i to 1.2 
inches. In Sugar Loaf Sound this average was maintained to the end of three 
years, when the experiment was abandoned for reasons already explained, 
while at the other two places it continued until the end of four years, when accu- 
rate records were lost as the result of disasters due to meteorological causes. 

Recent developments in Biscayne Bay indicate that the average growth of 
sponges planted on the bottom in Cape Florida Channel is slightly in excess of the 
rate stated above, while at Soldier Key, about 7 miles away, it is much less. At 
the first locality the currents are strong, the bottom muddy, and the neighboring 



A PRACTICAL METHOD OF SPONGE CULTURE. 



571 




572 



BULLETIN OF THE BUREAU OF FISHERIES. 




A PRACTICAL METHOD OF SPONGE CULTURE. 573 

banks covered with vegetation, while at Soldier Key the bottom consists of 
clean rock, the adjoining banks are sandy, and the current is probably less rapid, 
though of the latter I am not certain. The difference in the rate of growth may 
be due to the strength of the current or to the larger amount of food in the 
waters adjacent to marine vegetation. That the latter is the probable reason 
is indicated by recent observations that sponges planted on bottom covered by 
short grass at Soldier Key exhibit a more rapid rate of growth than those 
planted on bare rock. 

The slower rate of growth in the warmer waters of Sugar Loaf Sound was a 
surprise, and it may possibly be accounted for by the general absence of strong 
currents or by the character of the seed sponges. These were all small specimens 
rarely over 5 inches in diameter, obtained from the waters of the sound, which 
while formerly producing large ones now rarely do, possibly as a result of over- 
fishing in former years. In these shallow waters the spongers have been able 
rigidly to select out all marketable sponges, a process which would logically tend 
to eliminate those which grew rapidly and had an inherited tendency to reach 
larger dimensions, while leaving a preponderance of those of slower or stunted 
growth to perpetuate their kind. The inevitable tendency of an intensive fishery 
of this character would be to breed a race of more or less dwarfed sponges of slow 
growth, an assumption which is in a measure confirmed by the fact that Sugar 
Loaf Sound formerly produced a much greater proportion of large sponges than 
it does at present. This could not be due to the intensity of the fishery during the 
period within which I have been familiar with it, as the sound was then closed to 
promiscuous fishing and the sponges had ample opportunity to grow to larger 
size than the average attained. 

In Biscayne Bay and at Anclote Key the seed sponges were obtained from 
partially depleted beds, but owing to the greater depth and the more frequent 
prevalence of turbid water these have never been so thoroughly scoured of mar- 
ketable sponges. The specimens from which cuttings were made were larger, 
and presumably more virile, and in any event the cuttings grew more rapidly. 
At Sugar Loaf and Anclote Keys the planted sponges were measured at intervals 
after the first year by means of calipers, and occasionally specimens of average 
size were taken and cleaned. In Biscayne Bay local conditions prevented the 
systematic measurement of the sponges while growing. 

Text figures 4 and 5 exhibit graphically the rates of growth in volume of the 
cuttings at Anclote Key and Sugar Loaf Sound, respectively. The dotted lines 
indicate the theoretical increase in volume, assuming a uniform annual increase 
in diameter of 0.8 inch at Sugar Loaf and i inch at Anclote Key, while the 
heavy lines show the average growth of a number of measured specimens of the 
ages indicated by the position of the small circles. It will be observed that the 



574 



BULLETIN OF THE BUREAU OF FISHERIES. 



growth is fairly uniform up to the end of the fourth year, when there is a tend- 
ency to drop, but whether or not this late decrease in the rate is normal can 
not be stated, as the specimens measured had been injured by an influx of fresh 
water on the plantation. 

The experiments with wires appeared to show that sponges suspended 
above the bottom grow more rapidly than those on or near the bottom, but more 
recent results with disks and triangles appear to throw some doubt on this. It 
is probable that dense vegetation among which the sponges lay had an inimical 
effect and that sponges planted on bottom where they would not be covered 
by vegetation would grow as rapidly, or nearly so, as those suspended above it. 
With bottom planting it is difficult to make accurate and systematic observa- 
tions on a large scale, but such observations as have been made at Biscayne 
Bay and Anclote indicate that the rate of growth of cuttings planted on disks 
and spindles is at least equal to that of sponges planted on wires. 

The question has been raised in regard to sponge culture whether if a 
sponge be cut into pieces the total growth of the pieces will be greater than the 
increase of the same sponge would have been if it had remained intact, the 
environment being identical in the two cases. It has been argued with some 
plausibility that the reply to this question is in the negative, but experiments 
at Sugar Loaf Key do not bear out this assumption, and it was determined that 
entire sponges from 2^ to ^% inches in diameter grow at approximately the 
same rate as healed cuttings of the same volume each. They both increased 
in diameter at the average rate of about 0.8 inch per year, some individuals in 
each exceeding and some falling short of the average. The greater aggregate 
increase in volume, therefore, is obtained by cutting the sponges into pieces, 
and the smaller the cuttings, provided the minimum heretofore stated is not 
passed, the greater the advantage of subdivision. This is expressed graphically 
in figure 6, where the solid line represents the growth of an entire sponge 6 
inches in diameter, and the broken line the aggregate growth of a sponge of the 
same diameter cut into 20 and 50 pieces, respectively, making an allowance of 
5 per cent per year for mortality. The same data are shown in the following 
table. 



Comparative Increase in Volume of an Entire Sponge and the Aggregate ok Cuttings 
FROM Sponges of Equal Volume. 





Volume 

when 
planted. 


I year. 


2 years. 


3 years. 


4 years. 




Cu. in. 
168 

168 
168 


Cm. in. 

244 
399 
446 


Cu. in. 

343 

738 

1 .035 


Cu. in. 

464 

1,287 

1,932 


Cu. in. 
629 















A PRACTICAL METHOD OF SPONGE CULTURE. 



575 



It will be seen that at the end of four years the volume of 20 cuttings 
made from a 6-inch sponge will be over three times that which the same sponge 
entire would have attained under the same conditions, while 50 cuttings made 



























































































:::::: : :: : _ ; : :xX 3:: ".^ " ^ : : i" ^" :: 








.,.-.,- .... , . . ,. j J - ,■ ■■ ■ ■ ■ ^■' ■ 














- - - - - - _ . ' ^ 


















































.,==_, T ^^^._-=: .. 

















1 50 pieces 



Entire 
sponge 



No. of 

years after planting. i 204 

Fig. 6. — Comparative increase in volume of an entire sponge and of the aggregateof cuttings from spongesof equal volume. 

from a sponge of the same size will have a volume nearly 5 times as great. 
It should be explained, however, that these data do not represent a concrete 
case, but are based on observed rates of growth of cuttings and entire sponges 
under the same environment. The experiment begun to demonstrate these 
facts was interrupted by theft and vandalism. 



576 BUI.I.ETIN OF THE BUREAU OF FISHERIES. 

It should be stated also that 50 cuttings made from a 6-inch sponge would 
be smaller than has been found advisable and the rate of increase in diameter 
during the first year would be somewhat smaller than has been assumed, though 
thereafter it would be fully equal to that of the larger cuttings. 

MORTALITY. 

The data upon the highl}^ important question of the death rate among 
sponges grown from cuttings are not satisfactory. Buccich estimated it at about 
10 per cent in seven years, but my results indicate a somewhat higher rate. 

Owing to the unsatisfactory character of the supports which were employed 
during the early years of the experiment, it was necessary to shift the sponges 
from time to time, each handling resulting in some loss, and moreover the break- 
age of the lines often allowed the plants to fall to the bottom, where they were 
much injured b}^ adverse conditions. The mortality was highest at Anclote 
Key, where the plantation was exposed to the full force of the waves and the 
parting of the lines was frequent, and it was least at Sugar Loaf Key, where the 
greatest shelter was afforded. At Anclote there also was always more or less 
fall in the salinity during the heavy rainfall of summer, and the greatest mor- 
tality on the lines which remained intact was invariably coincident with this. 
Cuttings planted in the fall frequently reached the late spring months with a 
mortality of but i or 2 per cent, a rate increased to 8 or 10 per cent by fall. 
The observations made at that place are of value only as indicating the necessity 
for establishing the plantations in places not subject to the influence of freshets 
in neighboring streams. At Cape Florida, in Biscayne Bay, the plantation was 
more sheltered from boisterous seas, but the surface water was liable to fall in 
salinity during summer with a coincident increase in the death rate, though here 
the results were not so uniform. At this place various lots of sponges planted 
at different times and all subject to more or less of the vicissitudes of experi- 
mental work mentioned above, exhibited mortalities of 32 per cent at the end 
of fifty-three months, 29 per cent at the end of forty months, and 15 per cent at 
the end of twenty-six months, respectively. The first two lots were subject to 
damage from the breaking of the wires, but the last did not have this condition 
to contend with and the mortality during the last twenty-one months was equal 
to but 4 per cent of the original number planted. The heavy death rate of the 
first five months vv^as due to the sagging of the wire so that the cuttings lay 
among the dense vegetation, none of those raised above the top of the grass 
dying during that period. 

At Sugar Loaf Sound no difficulty was experienced with fresh water, and 
the death rate was correspondingly decreased. The lot of 400 cuttings having 
the longest period of growth at that place — thirty-five months — exhibited at the 
end of that time a mortality of 14 per cent. AH of these were transplanted at 



A PRACTICAL METHOD OF SPONGE CULTURE. 



577 



least once after having lain for an unknown time on the bottom vegetation 
under conditions which other experiments have shown to be inimical, and a 
considerable proportion of the deaths occurred at those times. Had the wires 
remained intact and the cuttings been kept always suspended above the vegeta- 
tion the death rate at the end of three years would undoubtedly have been 











^ 


^^ -- - - 




1 W^ITi Tl 1 NTl 


^^' _ . -. 


— — _ _ - — 








~2 ~ " "' ' : : 




t ~ -t " " 




^^s- - - 






















1 






. i ___ _,_„--- - 




'' "~r -1— 


/ 1 


y - - 


7 ' _________ 


























::::::::::::::::::::::::= = ;e4"::-:::::::::::::::::::::::- 


. J^ ~f"'~T' 



No. of 

months after planting.. I o 20 30 40 5° 60 

Fig. 7. — Percentages of mortality among different lots of sponges grown from cuttings at Sugar Loaf Key and 

Biscayne Bay. 

under lo per cent. Curves showing the percentage of mortality among different 
lots of sponges at Sugar Loaf Key and Biscayne Bay are shown in figure 7. 
These sponges were all on wires suspended above the bottom. 

At Anclote Key, owing to the almost constant turbidity of the water, it 
has been found impossible to determine the mortality among sponges planted 
on the bottom. At Cape Florida, in order to obtain data on this point and to 



578 BULLETIN OF THE BUREAU OF FISHERIES. 

avoid the error due to the Habihty to overlook disks from which the sponges 
may have become detached, practically all sponges planted on the bottom were 
attached to triangles either with or without spindles, each holding six cuttings. 
At that place the mortality at the end of six months was less than 3 per cent, 
and at the end of nineteen months a little less than 6 per cent, the latter including 
a few sponges in shoal water evidently detached by being fouled by the center- 
board of a boat, and at thirty months 9 per cent. At Soldier Key, also in Bis- 
cayne Bay, the death rate among sponges planted on triangles on smooth rock 
bottom was about 3 per cent at the end of ten months. Data relating to bottom 
planting for longer periods are not available, the first extensive experiment in 
this direction having been destroyed by the great hurricane of 1906. 

From the results recounted it is believed safe to assume that in localities 
free from influx of fresh water and the extensive deposit of silt or sand, with 
sponges planted on disks or triangles on rocky bottom, or on other bottom free 
from vegetation and stable enough to prevent the gradual sinking of the attach- 
ments, the mortality will be well below 5 per cent per annum. 

SHAPE AND QUALITY. 

Under artificial culture the shapes of sponges may be modified more or less 
to suit the special requirements of the arts. Sponges grown on wires or spindles 
assume a spheroidal shape with a uniform texture of surface and devoid of any 
semblance of a "root," such as is found in all natural sponges excepting rollers. 
This form is very attractive and durable. 

Cuttings grown on disks tend to assume a flatter shape and the surface 
attached to the cement is plane, in that respect resembling the root of natural 
sponges, but instead of being "raw" and exposing the canals it is covered with 
a close soft felt of great strength and durability, and forms the strongest instead 
of the weakest part of the sponge (pi. lxxvi). 

In certain arts and trades sponges with flat surfaces are required and to 
obtain these it is customary to cut the entire "forms" into pieces. The raw 
surfaces exposed in this way lack the durability of the natural surface and to 
obtain the latter, while at the same time retaining the several flat faces and 
sharp angles of the "cuts," a modified form of disk was employed. In this 
there were two partitions raised to a height of 4 inches, crossing one another at 
right angles on the upper surface of the disk. This left at the center of the disk 
four angular compartments, and in each of these a cutting was planted, which, 
being limited on three sides by the disk and two partitions, respectively, grew 
into a form having three plane surfaces at right angles to one another and one 
convex surface. The latter is similar in texture to the outside of an ordinary 
sponge, but the plane faces form contact with the disk and partitions and 



A PRACTICAL METHOD OF SPONGE CULTURE. 579 

develop a smooth, soft, and very durable felt-like surface. These sponges cost 
more to grow than those of ordinary shape, but experiments recently inaugurated 
will probably make the additional cost of production trifling. The superior 
durability of sponges grown in this manner should make it possible to market 
them at a price considerably above that brought by the natural product. 

It has been found that the sponges grown suspended above the bottom are 
superior in density and closeness of fiber to the natural sponges from the same 
locality. The same superiority is not apparent in those grown on disks, but 
the absence of the torn surface or root which characterizes the natural product 
makes them much more durable than the latter, the close felting of the attached 
surface making it the softest and strongest part of the sponge. In other words, 
the place of greatest weakness is converted into that of greatest strength, while 
the other parts remain normal. The artificially grown specimens are always 
superior to the natural product of the same immediate locality. 

At Anclote Key a considerable proportion of the sponges grown on the 
bottom are affected with so-called crab holes, cavities which commonly contain 
small crabs. The general opinion of the spongers is that the crustaceans pro- 
duce the holes, but of this I am by no means assured. As has been explained 
heretofore in this paper, practically all of the sponges planted on the bottom 
in this locality were previously injured by fresh water and already bore patches 
of dead tissue when planted on the bottom. As these dead areas sloughed away 
they left cavities, and I believe that these invited the crabs, which thus did not 
actually excavate their hiding places. In the many hundreds of these crab 
holes which I have examined in both artificially and naturally grown sponges 
I have never seen the slightest indication of a raw surface which looked as if 
the crab had torn away the tissues of the sponge. The presence of the crab, 
however, undoubtedly prevents the hole from filling up as it would tend to do 
under other conditions. In none of the healthy sponges planted on the bottom 
in Biscayne Bay do these holes occur, though they are found in the usual pro- 
portion in the natural sponges of the vicinity. 

HARVESTING. 

With the wire method of suspension from stakes, if such can be com- 
mercially developed, the problem of gathering the crop is simplified, for all 
that is necessary is to detach the wire at one end and slide the sponges off. 
As has been shown in the foregoing, however, this method has not yet been 
perfected and can hardly be commercially considered as yet. 

With bottom planting on disks or spindles the method of harvesting will 
vary with the depth of water. In comparatively shallow water the crop can 
be taken up when matured by means of hooks, and the conditions essential are 



580 BULLETIN OF THE BUREAU OF FISHERIES. 

the same as for ordinary sponging — the weather must be moderate and the 
water clear. In deep water, beyond the reach of the hooks, it will be necessary 
to employ divers to gather the sponges, which will materially increase the 
capital required and the expense of operation. As has been explained pre- 
viously, the operations of harvesting and replanting can be economically com- 
bined. 

TRANSPORTATION AND ACCLIMATIZATION. 

The transportation of seed sponges by water has been dealt with in another 
connection, but experiments indicate that they can also be carried considerable 
distances overland if proper precautions be observ^ed. With the air temperature 
ranging between 70° and 80°, specimens have been easily kept without injury 
by merely packing them in wet seaweed in tubs. Others have been shipped by 
express, closely packed with wet eel grass and gulf weed (sargassum) in orange 
crates, over distances requiring three days between the time of removal from 
the water and the time of replanting. Although carried in heated express cars 
they were absolutely uninjured and started growth immediately after trans- 
planting. Of another lot shipped on a six days' journey under the same condi- 
tions nearly all were killed. 

If kept cool, the sponges will live much longer, and there is reason to believe 
that if carried in moist packing in refrigerator cars there would be little doubt of 
their surviving a trip extending over one week. Thus, with proper arrangements 
Florida sponges could be carried alive to the California coast. With similar 
arrangements and with the facilities which would be afforded for giving the 
sponges occasional refreshing baths in sea water it is believed that little diffi- 
culty would be experienced in carrying specimens from the Mediterranean to 
Florida. The water used in moistening the sponges and the packing material 
must be of full oceanic salinity, an experiment having shown a mortality of 
50 per cent among sponges sent on a three-day journey when a portion of the 
packing material was inadvertently moistened with nearly fresh water from 
Anclote River. 

But while there may be little difficulty in transporting sponges to distant 
places and acclimating them in suitable waters, there is grave doubt if they will 
retain the characteristics which they exhibit in their original habitats. Sponges 
from the vicinity of Anclote Key transplanted to Biscayne Bay undoubtedly 
gradually developed some of the characters of indigenous specimens, but unfor- 
tunately the experiment to determine this point conclusively was seriously 
interfered with by a hurricane which intermingled the various lots. All of 
the transplanted specimens which could be definitely identified, about 15 in 
number, had completely lost their original characteristics at the end of two 



A PRACTICAL METHOD OF SPONGE CULTURE. 58 1 

years, and it is probable that one not knowing their history would be unable 
to distinguish them from those grown from indigenous seed. The close-set 
bristles which cover the surface of wire-grown sponges at Anclote have been 
replaced by fiat brushes of fiber, the oscula, formerly inconspicuous, have 
become larger and resident on the summits of short tubular processes, the 
general texture of .the sponge is more open, and, finally, the fibers have become 
thoroughly charged with the characteristic red color of the Key sponges. In 
some specimens the red coloration is more pronounced than is normal in the 
locality to which the sponges have been transplanted. 

At Anclote, also, it was observed that whatever the source of the seed 
there was a strong tendency of the plants to advert to a common type, though 
there appeared to be a tendency ta compromise between the influences of 
heredity and environment. Deep-water sponges a year after the cuttings were 
planted assumed the bristly appearance above referred to, but the processes 
were shorter and blunter than in sponges grown from shoal-water seed. The 
texture of the skeleton was also closer and more dense than in the cuttings of 
shoal- water origin, but neither resembled very closely the sponges from which 
they were derived. With these facts in view, it is almost certain that Florida 
sponges transplanted to the California coast, or Mediterranean specimens car- 
ried to the waters of Florida, will not retain their original characters, but it 
does not follow that they will be inferior. It is even possible that with judi- 
cious selection localities may be found where the transplanted products may 
prove superior to their fellows at home, though it is true that one can hardly 
expect to improve on the quality of the fine sponges of the Mediterranean. 

ECONOMIC APPLICATION OF THE METHOD. 
ESSENTIAL CONSIDERATIONS. 

The choice of a locality for commercial sponge culture is a highly important 
consideration. In the first place, it must be one that can be guarded, for what- 
ever the law may be it can not enforce itself, as has been amply demonstrated 
by the history of the oyster industry and some of my own experience in sponge 
culture. For this reason the small planter will have to select his location near 
shore, where he can live and himself guard his property, and this practically 
restricts the choice for such persons to the region of the keys. The large planter, 
employing a number of persons, can aftord to station a guard boat on his planta- 
tion, and can therefore carry on his operations farther from shore and on the 
high seas. 

Selection also must be made of a locality not subject to the effects of 
freshets and heavy rainfall on the adjacent mainland, and for this reason the 



582 BULLETIN OF THE BUREAU OF FISHERIES. 

vicinity of the mouths of rivers must be avoided. The water should at all times 
be of a saltness not much below that of the open sea, and no locality where it 
frequently falls below a specific gravity of 1.019 or 1.020, reduced to a standard 
temperature of 60° F., can be regarded as safe. Disastrous experience on the 
plantations of the Bureau and of Messrs. Cheyney and Bigelow at Anclote Key, 
where the density, especially near the surface, fell below 1.018 for a consider- 
able period and killed the majority of the sponges, emphasizes this considera- 
tion. Along the keys below Lower Matecumbe or between the upper end of 
Key Largo and Cape Florida this trouble is not likely to be experienced, but 
there are few places near the mainland opposite the keys or in the Gulf of 
Mexico, where localities close to shore can be occupied without apprehension 
from this cause. Several years may interv^ene between successive periods of 
fresh water, and the fact that it does not occur for one or two years does not 
guarantee that a plantation will not experience its effects just when the planter 
is beginning to hope to reap the results of his labor. With this consideration 
firmly in view, there is no great difficulty in avoiding most of the disasters 
which have affected the experimental work. 

The experiments with wires and lines for the suspension of the cuttings 
above the bottoms having not reached favorable termination, the use of soft 
muddy or densely grassy bottom can not be recommended, and the sponge 
grower is, therefore, practically restricted in his choice to such bottom as is 
more or less capable of supporting a natural growth of sponges. Disks and 
triangles tend to sink on mud marl or shifting sand, or are overgrown when 
deposited among dense marine vegetation, in any of which contingencies the 
cuttings are either killed or injured. Even when the sponge is but partially 
buried in sand the basal portion will die from suffocation, and the still living 
upper parts will eventually lose attachment and be carried away. But a sparse 
growth of grass may prove highly beneficial in stimulating a more rapid growth 
of the sponges. This appears to be indicated by very recent experiments, and 
if it should prove true a large area of virgin bottom will be opened to produc- 
tiveness. Otherwise, the selection of a sponge farm is practically limited to 
rocky bottom, though there are occasional localities where a mud bottom com- 
paratively free from vegetation is sufficiently firm to support disks or triangles. 

Care must be exercised also to avoid places where there is much sand car- 
ried in suspension in the water, as this will be deposited in eddies created by 
the sponges and their supports, and will gradually build up around the plants. 
This difficulty can be avoided on otherwise suitable bottom by raising the cut- 
tings on spindles, so as to allow the currents to have a scouring action below 
the growing sponges. For attachments it is recommended that the disks 
described in a previous section of this paper be employed. The plain disk per- 
forated by two holes is the simplest and cheapest form of attachment, but its 



A PRACTICAL METHOD OF SPONGE CULTURE. 583 

use involves more labor than when the form with a short lead wire spindle is 
used. The cuttings should be bound to the disk by short pieces of no. 14 or 
no. 16 Brown & Sharp gauge aluminum wire, passed through the substance of 
the cutting, and thence through the holes in the disk, the ends twisted together 
below. 

The cuttings should be made as already described, and should have prefer- 
ably a volume of 8 to 10 cubic inches, measuring, say, i J^ by 2 J< by 3, or a little 
less. They should be made as regular as is convenient without the expenditure 
of additional labor. They can be handled and exposed to the air without special 
precautions, but should not be allowed to remain in foul water. 

If the disks with short spindles are used, the cuttings may be merely threaded 
on to the spindle by means of a needle, as has been already described, the cut- 
tings being pushed down into contact with the cement disk, to which, as well 
as to the spindle, they soon grow fast. The process is much more rapid and less 
laborious than wiring the cuttings to the plain disks, which fact almost com- 
pensates for the increased cost of material. 

The triangles are not recommended excepting when it is necessary to use 
long spindles to raise the sponges above possible sand deposit, in which event 
they are less liable than the disks to capsize under the impact of the waves 
against the larger sponges. They are more difficult to handle and transport 
than are the disks, and more easily broken. When fitted with 8-inch spindles 
of lead-covered iron ribbon, they cost about twice as much per sponge as do the 
disks, and the greater labor of transporting to any considerable distance will add 
to the difference in cost. 

In shoal water the disks or triangles with the cuttings attached may be 
dropped overboard right side up. They will in the great majority of cases sink 
to an upright position on the bottom, though occasionally, in strong currents, 
one will capsize in its descent. Advantage should be taken of the first oppor- 
tunity to inspect the planting, to right the capsized disks, and to shift any that 
may have fallen on those already planted. In deep water there is greater 
liability that the disks will capsize; the danger is less with triangles. Though 
the experiment has not been tried, it is probable that an inclined chute, one 
end resting on the bottom and the other coming to the side of the boat, down 
which the disks could slide, would not only insure an upright position of the 
disks, but would generally facilitate planting. As the boat was hauled ahead 
the disks would be distributed over the bottom in rows. 

FINANCIAL ASPECTS. 

The cost of planting will vary somewhat with the locality, but the following 
figures, based on actual experience at Anclote Key, are fairly representative of 
what may be regarded as average conditions. The computation is based on 



584 BULLETIN OK TllK IJUKICAU OF FISHERIES. 

the requirements for ])Uiiitins; i acre with a sponge on each square yard of 
bottom. 

For plain disks: 

4,840 disks, at 2 cents $96. 80 

4,840 cuttings, at 2 cents 96. 80 

Labor, planting, fifteen days, at $2 30. 00 

223. 60 
For disks with short lead spindles: 

4,840 disks, at 2>2 cents 121.00 

4,840 cnl tings, at 2 cents — 96. 80 

Labor, six days, at $2 .. 12. 00 



229. 80 

The lirst cost is shghtly in favor of the plain disks, the expense for aluminum 
binding wire being so small as to be negligible, but when it is remembered that 
both kinds of disks are availa1)le for subsequent plantings when recovered, this 
advantage disappears. Assuming that during four years of growth 20 per cent 
of the original cuttings die and that the disks to which they were attached are 
lost on account of their inconspicuousness, each of the above accounts would 
have to be credited with the value of the disks recovered, 80 per cent, amounting 
to $77.44 in the first case and $96.80 in the second, making the actual cost of 
planting in the two cases $146.16 and $133, respectively. 

In sul)se(iuent use of the disks for replanting, especially in deep water 
where a diver is employed, the advantage is strongly in favor of the disks with 
spindles for reasons that have been already explained. The cost of harvesting 
the sponges can not be stated, as there are no adequate data available. In 
shoal water, where the sponges could be taken by hooks and the replanting 
with fresh cuttings be carried on simultaneously, the cost would be slight. 
Where a diver woidd have to be employed the expense would be heavier, but 
by using the spindles this coidd also be reduced by planting fresh cuttings as 
fast as the niatin"e sponges are taken, without removing the disks from the 
bottom. In most localities in deep water there would also be a compensatory 
greater return on accoimt of the superior quality of the sponges. 

Assuming that there is no expense in guarding the beds, but that this 
service is incidentally i)erfornied by the men making the disks and planting the 
sponges, the a[)pareiit profits to be derived from sponge jjlanting are as follows: 

Net cost of i)lanting I acre with 4,840 cuttings $^33, 

Value of 3,872 sponges (80 per cent of 4,840), at 2^5 cents 968 

Thus, at the end of four years from the date of planting, the net value of 
the sponges on the bottom would be $835, assuming that they had grown at the 
rate demonstrated at Anclote Key and had attained an average weight of 
ij,^ ounces, dry, that the mortality during their growth was 20 per cent, and that 



A PKACTICAL METHOD OF SPONGE CULTURE. 585 

the value of pure sponges is $4 per pound, which is less than the average of 
recent years. These assumptions are all regarded as very conservative. 

From this must be deducted the cost of harvesting, which, in shallow water 
such as is to be found among the keys, should not exceed about $25 if proper 
conditions of weather and water be availed of. The net return, therefore, from 
an original investment of about $225 per acre would be an average of about 
$200 per year. In deeper water the cost of harvesting the crop would be some- 
what greater, but as the operations would be carried on on a larger scale econ- 
omies could be practiced which would reduce the expense. 

In conclusion it should be plainly stated that the above calculation, though 
based on the actual results of experiment, is largely theoretical and that definite 
data can not be attained until the work is actually undertaken on a commercial 
scale. It is confidently believed, however, that if directions are followed in a 
suitable locality the actual net returns per acre will be considerably greater than 
those stated. 



Plate LXIX 



Fig. 1 . — Sheepswool cutting of about the size recommended for 
planting. 



Fig. 2. — Sheepswool sponge 1 1 months old, grown on wire at Anclote 
Key from a cutting about one-half size of figure 1 . 
Natural size. 



Plate LXX 



Fig. 1 .— Sheepswool sponge 20 months old, grown on wire at Anclote 
Key from a cutting about one-half the volume shown in 
figure I , plate Ixix. 



Fig. 2.— Yellow sponge 21 months old, grown on wire at Sugar Loaf 
Key from a cutting about the size shown in figure 1 , plate 
Ixix. Natural size. 



q39fI8 . f .gil 

.xixi aJfilq , i 3iu§H 



-'oqe woIIsY — .£ .giT 
.3SI3 lfiiuJfiI4 .xixi 














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Plate LXXI 



Sheepswool sponge 3 I months old, grown on wire at Anclote Key 
from a cutting about one-half the volume shown in figure 1, plate Ixix. 
Nine-tenths natural size. 



IXXJ eisH 

yayl sJoIonA is aiiw no nwoig ,bIo sdinom I ^ agnoqg looweqaarlc^ 
.xixl sislq , ( aiugri ni nwoHa amulov arlj HsH-ano Juodfi gniJJuo b moi-1 

.3X18 IfiiuJBn eHjnsJ-dniM 



Plate LXXII 

Sheepswool sponge 35 months old, grown on wire at Sugar Loaf 
Key from a cutting about the size shown in figure 1 , plate Ixix. 
Nine-tenths natural size. 



IIXXJ alsiq 

IboJ ib^u?. Jb 911 w no nwoig ,bIo arljnom ^^ ^^aoq?. loowsqaariS 
.xixl aJelq , ! aiugil ni nwoHs asie aril Juods xjniiJuD b moi\ x^j^ 

.3X18 iBiuJfin aHjnaJ-sniM 



Plate LXXIII 

Sheepswool sponge 52 months old, grown on wire at Cape Florida 
from a cutting about one-half the volume shown in figure I , plate Ixix. 
Weight, dry and thoroughly cleaned, 1 ^3 ounces. Nine-tenths natural 



IIIXXJ 3)bR 

.xixl aJsIq ,[ siugrl ; raulov sHj llfiH-ano JuocIb gniMuD fi moil 

IfiiuJBn sdinai-oaWi .<'.jjauo i[ I ^banBsb ylHguoioHj has ^ib ^HgiaW 

.3X18 



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Plate LXXIV 

Sheepswool sponge 35 months old, grown on spindles (plate Ixvil) 
in Cape Florida Channel from a cutting about the size shown in 
figure 1 , plate Ixix. Weight, dry and thoroughly cleaned, I y^ 
ounces. Nine-tenths natural size. 



VIXXJ aJfilS 

(iivxl aJiilq) salbniqa no nv/oig ,bIo eHjnom ^£ agnoqa loowaqaaHS 
ni nworl;-. 3si8 odi Juoob gniJluo s moi-1 hnnsAD fibiioR aqfiO ni 
^^ [ ,b3n63b \[i{i!^' " '-'nG vib .JrigiaW .xixl aJfilq ,1 aiugri 

.3X18 IfiiulBfl eHjnaJ-omH .^^Dauo 



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Plate LXXVI 

Sheepswool sponge not over 48 months old, grown on a cement 
disk at Anclote Key from a cutting about the size shown in figure 1 , 
plate Ixix. Weight, dry and thoroughly cleaned, I Yz ounces. Nine- 
tenths natural size. This illustration shows the closely felted soft 
surface in contact with the disk. The corresponding surface of a 
natural sponge is open, like the interior, and therefore weaker and less 
durable. 



IVXXJ eisH 

JnamsD b no nwoig ,bIo erlJnom 8^ lavo Jon agnoqa looweqaarlS 
, I 3iugB ni nwoHe 3X18 arlj juocIb gniJJuo b moii ^ayl sJoIonA Jb ilaib 
-3niI4 .83onuo a^ ( ,b3nB3lD ^IHguoioHl bnB \ib .irlgiaW .xixl aJBlq 
jio8 bsJiai x^^^oId sHj ewoHa noilBiJauIIi eiHT .asie iBiuJBn erllnai 
B lo aofilius gnibnoqesnoo arlT .:jl?iib arij Hjiw JoBJnoo ni aDshua 
^^^[ has la^Bsw sioiaiailj bnB ,ioii3Jni arii a^lil .naqo ei 3§noq2 IbiuIbh 

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